Workers examine a sinkhole on a Portland street in April.Brent Wojahn/The Oregonian

Tom Miller, director of Portland's Bureau of Transportation, told a budget advisory group Tuesday to expect a final report on possible new revenue streams for the financially challenged bureau by mid-December.

The draft raises the possibility of a new street maintenance fee -- an idea that Mayor-elect Charlie Hales raised unsuccessfully when he was a city commissioner, in 2001, and that Mayor Sam Adams tried and failed to get in 2008, when he was also a city commissioner.

It also addresses the possibility of a new Portland gas tax, as The Portland Mercury first reported. (Side note: In 2009, House Bill 2001 increased the state gas tax and other vehicle fees, while also putting a moratorium on local gas tax increases. That prohibition ends in January 2014.)

But the draft doesn't stop with those two items. It also proposes a commercial parking tax such as the one in Seattle, inflation-indexed rates for parking meters and city-owned garages, higher parking rates for special events and general obligation bonds.

Miller told the budget advisory group Tuesday that he expects Hales, who takes office in January, and the next City Council to take up the issue -- not Adams or the current City Council.

Several other Oregon cities have street maintenance fees, which raise money to repave roads and make other street improvements. "This is not a novel concept," Miller said. "Arguably, it is time for Portland to establish one for itself."

Passing one would take considerable political support, however.

In recent years, city audits have noted that Portland officials have made deep cuts to road maintenance budgets and fallen behind significantly on road repairs. City streets represent Portland's single biggest asset.

Hales, in an interview Wednesday, said he wouldn't tackle the issue of a street fee or gas tax immediately. "Not right away," he said. "I'm not at all unwilling to think about new revenue," he added. But he said he wanted to get the bureau's financial "house in order" first.

Meanwhile, city transportation officials are exploring another option that they and the mayor hope will save the agency money: They want to replace thousands of high-pressure sodium streetlights, which last about five years, with LED bulbs, which can last more than 20 years and use about half the energy.

The financing deal, which went before the City Council for a reading on Wednesday, is complicated. The bureau would issue a total of $18.5 million in revenue bonds -- starting with $6.5 million in 2013 -- to convert streetlights and buy new poles. Debt service would range from $300,000 in the first year to $660,000 in out years during the first phase. "Debt service payments will be funded by savings realized from reduced energy, maintenance, and operations costs associated with the conversion," the city argues.

But the city also expects additional savings beyond what would cover debt payments. That money would go toward a fund for replacing the LED components when they give out, city officials say.

Other cities, including Los Angeles, have already made the switch to LED. Miller said the time was right for Portland to follow because prices on the technology have fallen.

"Prices are still going to go down," one member of the budget group told Miller on Tuesday. "Don't rush."